1. Field of the Invention
This invention relates in general to multibeam satellite switching networks, and, in particular, to a dynamic repeater configuration for multilink satellite systems with subchannel interconnect capability.
2. Description of Related Art
Communications satellites are operated in various modes. Some satellites operate as simple repeaters, typically known as a xe2x80x9cbent-pipexe2x80x9d configuration, where the uplink signal is merely repeated, at a different frequency, in a downlink signal. No processor capability is available onboard the satellite other than frequency translation between the uplink and downlink signals, and, if necessary, amplification of the downlink signal to allow ground based receivers to receive the signal.
Multi-beam satellites were introduced to allow the satellite to receive signals from multiple sources and relay those signals to multiple destinations. In a multi-beam satellite, however, the ability of the satellite to relay a given uplink signal to a desired downlink destination was still limited.
To help to reduce this limitation, multi-beam satellites that have on-board switching capability have been deployed. These satellites receive an incoming beam containing several frequency-multiplexed channels, demultiplex (demux) the signal on-board the satellite, and inter-beam switch these channels into a desired downlink beam.
The multi-beam switching satellites, however, are still limited in their switching capabilities. A subchannel of a given uplink frequency must still be located at the same relative frequency in any one of the subchannels of the downlink frequency. Further, channels are limited in the same manner, i.e., a channel of a given uplink frequency must be located at the same relative frequency in the downlink frequency. These limitations are undesirable because they limit the multiplexing of uplink and downlink channels and subchannels for flexibility in providing communication services to geographically diverse satellite ground stations.
Further, the present multi-beam switching satellites are limited in that an uplink channel or subchannel can only be routed to a single downlink channel, and an uplink subchannel can only be routed to a single downlink subchannel. This limitation further reduces the flexibility of the satellite communications.
It can be seen, then, that there is a need in the art for a multi-beam switching satellite that can multiplex any uplink channel or subchannel into any downlink channel or subchannel frequency slot. It can also be seen, then, that there is a need in the art for increased flexibility in the subchannel interconnections between uplink frequencies and downlink frequencies. It can also be seen that there is a need in the art for a multiplexer system that can route an uplink channel or subchannel into multiple downlink channels or subchannels, respectively.
To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention discloses a dynamic repeater configuration for multi-link satellite systems. A dynamic repeater configuration for satellite systems is disclosed that allows for multiple broadcast of channel information and multiple subchannel allocations on uplink and downlink beam signals. The apparatus comprises an input multiplexer, a subchannel routing switch matrix, a channel routing switch matrix, and an output multiplexer. The input multiplexer receives the uplink signal and produces at least a first channel signal therefrom. The subchannel routing switch matrix receives the uplink signal, separates at least one channel signal into at least one subchannel, routes the subchannel from a selected uplink subchannel into a selected downlink subchannel, and recombines the selected downlink subchannels into a second channel signal. The channel routing switch matrix routes the first channel signal into a first downlink channel signal and the second channel signal into a second downlink channel signal. The output multiplexer combines the first and second downlink channels into the downlink signal.
As further flexibility in the repeater system becomes necessary, additional hardware can be added, or the configuration can be rearranged, to allow for the channels and subchannels to be reconfigured, e.g., multiple subchannel allocations, broadcast of a single uplink channel into multiple downlink slots, and other options.
An object of the present invention is to provide a multi-beam switching satellite that can multiplex any uplink channel or subchannel into any downlink channel or subchannel frequency slot. A further object of the invention is to provide increased flexibility in the subchannel interconnections between uplink frequencies and downlink frequencies. A further object of the invention is to provide a multiplexer system that can route an uplink channel or subchannel into multiple downlink channels or subchannels, respectively.